1. Field of the Invention
This invention relates to a gas-discharging type display device, and more particularly, to the gas-discharging type display device which has both an anode and a cathode facing each other in an airtight chamber filled with a gas, and a production method for such a device.
2. Description of the Prior Art
In the conventional technique, a panel-shaped gas-discharging type display device 90, shown in FIG. 20, is composed of a rear insulating substrate 92 with a plurality of belt-shaped cathodes 91 and a front transparent insulating substrate 94 with a plurality of belt-shaped transparent anodes 93. Both rear insulating substrate 92 and front insulating transparent substrate 94 are arranged such that each belt-shaped cathode 91 faces a corresponding anode 93 a predetermined distance apart and are crossed to each other. Both rear insulating substrate 92 and front insulating transparent substrate 94 form an airtight chamber 95 by processing the sides, which is filled with a gas including Xe (xenon) for ultraviolet emission.
A plurality of front barrier ribs 96 are formed on the surface of rear insulating substrate 92 and front insulating transparent substrate 94 in airtight chamber 95. A plurality of discharge cells 97 are disposed in a rectangular array at the junction of each belt-shaped cathode 91 and belt-shaped transparent anode 93. A spacer 98 is located between rear insulating substrate 92 and front barrier rib 96. A space 99 is formed next to spacer 98 so as to connect discharge cells 97. A fluophor 100 is applied to the inner wall of rear insulating substrate 92 and along front barrier rib 96.
Belt-shaped cathode 91 is produced by applying an emitter material, containing LaB.sub.6 as a main ingredient, to a cathode base of Ag.multidot.Pd (silver.multidot.palladium) paste and the like by plasma spray coating. The emitter material lowers a threshold voltage for discharging, and further increases the anti-spatter property.
A direct-current voltage is selectively biased between belt-shaped transparent anode 93 and belt-shaped cathode 91. Discharging is controlled to occur at desired discharge cell 97. Ultraviolet emission generated by the discharging excites fluophor 100, resulting in a light emission through belt-shaped transparent anode 93 and front insulating transparent substrate 94, which color corresponds to fluophor 100. Thereby a desired character and figure can be seen outside. In discharging, ions are transferred between discharge cells 97 through space 99.
Referring to FIG. 20, the prior art panel-type gas discharge display device includes a negative electrode shaped as a flat band, or belt-shaped. Therefore, during operation, the discharge tended to occur only within the relatively small confines of the discharge cell. This limitation made it difficult to achieve an adequate brightness.
A problem with the conventional device, however, is that its brightness rapidly decreases and the color becomes unstable for a long period of time. Furthermore, since the device is relatively thin, discharging occurs only in a limited space, thereby making its brightness unsatisfactory for a display device.